WO2020149381A1

WO2020149381A1 - Press-formed article manufacturing method, and press line

Info

Publication number: WO2020149381A1
Application number: PCT/JP2020/001371
Authority: WO
Inventors: 隆一西村; 鈴木　利哉
Original assignee: 日本製鉄株式会社
Priority date: 2019-01-17
Filing date: 2020-01-16
Publication date: 2020-07-23
Also published as: JP7081691B2; EP3912743A4; JPWO2020149381A1; EP3912743A1; US20220118499A1; US11878334B2; CN113365750B; CN113365750A

Abstract

This press-formed article manufacturing method includes: individually acquiring the warpage of each sheet material to be pressed; and press-forming each sheet material into a press-formed article using a die 6, a punch 7, and a movable mold 9. In said press-forming, the initial position of the movable mold 9 with respect to the die 6 or the punch 7 is controlled on the basis of the warpage of the sheet material.

Description

Method for manufacturing press-formed product and press line

The present disclosure relates to a method for manufacturing a press-formed product and a press line.

In press molding, there is a technology to improve the dimensional accuracy of the press molded product by making part of the mold movable. For example, Japanese Patent No. 6179696 (Patent Document 1) discloses a press device including a die having a die pad and a punch arranged to face the die and having an inner pad. There is.

Japanese Patent No. 6179696

In press molding, all plate materials in the same production lot are press molded under preset press conditions. That is, if the deviation of the shape of the first press-formed product from the target shape is within the tolerance, the subsequent press-forming is also performed under the same press conditions as those of the first press-formed product.

In the case where the properties of a plurality of plate materials vary, the inventors of the present invention do not obtain the desired shape of the press-formed product to be press-formed later even if the shape of the first press-formed product is the desired shape. I noticed that there is.

The present specification discloses a method for manufacturing a press-formed product and a press line that can reduce the deviation or variation of the shapes of a plurality of press-formed products from the target shape.

The method for manufacturing a press-formed product according to the embodiment of the present invention, the warp amount of one or a plurality of plate materials to be pressed is individually acquired for each plate material, a die, a punch, and both the die and the punch. Press-molding the plate material into a press-formed product by a movable mold whose relative position can be changed. In the press molding, the initial position of the movable die with respect to the die or the punch is controlled based on the warp amount of the plate material.

According to the present disclosure, it is possible to reduce the deviation or variation of the shapes of a plurality of press-formed products from the intended shape.

It is a figure which shows the structural example of the press line in this embodiment. It is a perspective view which shows the structural example of a press apparatus. It is a figure for demonstrating an example of the relationship of the measurement direction of the amount of curvature of a press object board, and the direction of a punch ridgeline. FIG. 3B is a diagram for explaining an example of measuring the amount of warpage of the plate to be pressed in the x direction in FIG. 3A. It is a figure for demonstrating the other measurement example of the amount of curvature of a press target board. It is a figure which shows the example of press molding. It is a figure which shows the example of press molding. It is a figure which shows the example of press molding. It is a figure which shows the example of press molding. It is sectional drawing which shows an example of a press-molded article. It is a flowchart which shows the operation example of a controller. 6 is a graph showing an example of the correlation between the protruding amount of the inner pad and the shape of the press-formed product. 6 is a graph showing an example of the relationship between the appropriate protrusion amount of the inner pad and the warp amount of the blank in the width direction. It is a graph which shows an example of the relationship between the amount of suitable protrusion of an inner pad, and the amount of warpage of the blank in the longitudinal direction. 7 is a histogram of the amount of warpage and the positional accuracy of the flange when feedforward control is performed based on the amount of warpage. 6 is a histogram of the amount of warpage and the positional accuracy of the flange when feedforward control based on the amount of warpage is not performed.

The plate material before press molding may be slightly warped. For example, the warp amounts of a plurality of plate materials included in the same manufacturing lot are often different. The inventor paid attention to the warp amount of this plate material. As a result of investigating the relationship between the amount of warp of the plate material before press molding and the shape of the press molded product after press molding, it is possible that variation in the amount of warp of multiple plate materials can cause variation in the shape of the press molded product. all right. In particular, it has been found that when forming the groove-shaped member by press molding, the warp amount of the plate material before the press-molding tends to affect the shape of the groove-shaped member after the press-molding.

Therefore, we investigated a method to suppress the variation in the shape of the press-formed product due to the variation in the amount of warpage of multiple plate materials. As a result of earnest studies, it was found that there is a correlation between the warp amount of the plate material before press molding and the initial position of the movable die used for press molding with respect to the die or punch. Based on this knowledge, it was attempted to control the initial position of the movable mold in the press molding with respect to the die or punch according to the warp amount of the plate material. It has been found that control of the initial position of the movable mold based on the amount of warp can suppress variations in the shape of the press-formed product. The following embodiments have been conceived as specific examples.

(Method 1)
The method for manufacturing a press-formed product according to the embodiment of the present invention, the warp amount of one or a plurality of plate materials to be pressed is individually acquired for each plate material, a die, a punch, and both the die and the punch. Press-molding the plate material into a press-formed product by a movable mold whose relative position can be changed. In the press molding, the initial position of the movable die with respect to the die or the punch is controlled based on the warp amount of the plate material.

According to the above manufacturing method, the initial position of the movable mold with respect to the die or punch during press molding is controlled according to the warp amount of the plate material. By controlling the initial position, the shape of the press-formed product is adjusted according to the warp amount of the plate material. Therefore, it is possible to suppress the deviation or variation of the shapes of the plurality of press-formed products from the target shape due to the variation of the warp amounts of the plurality of plate materials.

The initial position of the movable mold is the relative position of the movable mold to the die or punch in the initial stage of each of the plurality of press moldings. In each press molding, the press molding is performed by bringing the die and the punch relatively close to each other from the state where the movable mold in the initial position is in contact with the plate material. The initial position of the movable mold is the position of the movable mold before the operation of bringing the die and the punch relatively close to each other.

For example, the movable mold may come into contact with the part of the press-molded product (finished product) that will be the product during press molding. In this case, the movable mold controls the shape of the press-molded product (finished product). Depending on the initial position of the movable mold, it is possible to control the subtle shape of the press-molded product.

The movable mold may move relative to the die or punch during one press molding. Examples of possible dies of this type include punch pads (inner pads), die pads, blank holders and the like. Alternatively, the movable mold may be fixed in its relative position with respect to the die or punch during one press molding. That is, the movable mold may not move (do not move) with respect to the die or the punch during one press molding. It should be noted that one press-molding is a press-molding performed by a set of a die, a punch and a movable die to make one press-molded product.

(Method 2)
In the above method 1, the press forming may include continuously press forming a plurality of plate materials. The initial position of the movable die with respect to the die or the punch may be controlled based on the warp amount of the plate material at least once in a plurality of continuous press moldings. As a result, in a plurality of press-formed products produced by a plurality of continuous press-formed products, it is possible to suppress variations in the shape of the press-formed products due to variations in the amount of warpage.

(Method 3)
A method for manufacturing a groove-shaped member according to an embodiment of the present invention is a method for manufacturing a groove-shaped member that includes a top plate, vertical walls extending from both ends of the top plate, and a ridge line between the top plate and the vertical wall. Is the way. The manufacturing method, to obtain the amount of warp of the plate material, the plate material, the die, and arranged between the punch provided with an inner pad on the top, the initial position of the inner pad with respect to the punch, the obtained Setting based on the amount of warp, in a state where the initial position of the inner pad with respect to the punch is set, the die and the punch are brought relatively close to each other, and the die shoulder of the die slides on the plate material. Forming the vertical wall, and forming the top plate by pressing the plate material with the top of the punch accommodating the inner pad and the die.

According to the above manufacturing method, the initial position of the inner pad with respect to the punch during press forming is set based on the amount of warpage of the plate material. An appropriate initial position is set according to the warp amount of the plate material. As described above, the die and the punch relatively approach each other in a state where the initial position of the inner pad is set based on the warp amount, and the vertical wall is formed while sliding the plate material by the die mold. Further, with the inner pad housed in the punch, a plate material is sandwiched between the punch and the die and pushed to form the top plate. As a result, by controlling the initial position of the inner pad according to the warp amount of the plate material, the shape of the groove-shaped member to be press-formed is adjusted according to the warp amount. As a result, it is possible to suppress deviations and variations in the shapes of the plurality of press-formed products from the target shape due to variations in the warp amounts of the plurality of plate materials in the manufacturing lot.

As an example, the punch includes a protrusion protruding toward the die. The die includes recesses that correspond to the protrusions of the punch. The movable mold is provided, for example, on at least one of the convex portion of the punch and the concave portion of the die. It is an example of a movable mold. The inner pad, which is an example of a movable die, is provided on the top of the convex portion of the punch. The inner pad is provided so that it can project from the top of the punch toward the die and can be stored on the top of the punch. The initial position of the inner pad may be set, for example, by the allowance from the punch of the inner pad. The allowance for the inner pad is the height of the inner pad protruding from the top of the punch. A die pad, which is an example of a movable die, is provided at the bottom of the recess of the die. The die pad is provided so as to project from the bottom of the recess of the die toward the punch.

The amount of warpage of the plate material may be measured in at least one direction. It is preferable to measure the amount of warp of the plate material in two or more different directions from the viewpoint of suppressing deviation and variation from the target shape of the press-formed product due to warp of the plate material. For example, the warp amount of the plate material may be measured in two different directions in the plane of the plate material.

The plate material for which the amount of warp is measured is the plate before press molding using a die and a punch with an inner pad. As the plate material, for example, the amount of warp of a blank (flat plate) may be measured, or the amount of warp of an intermediate molded product obtained by intermediately molding the blank may be measured. The warp amount of the entire plate material may be measured, or a part of the warp amount may be measured. For example, the amount of warpage of the portion of the plate material that serves as the vertical wall may be measured. The warp amount is measured with respect to a plate material or a part thereof which should originally be a flat surface (that is, the warp amount is 0). For example, the amount of warpage can be the amount of deviation from the plane.

(Method 4)
In the above method 3, it is preferable to measure, as the warp amount of the plate material, a first warp amount in the extending direction of the ridge line and a second warp amount in a direction perpendicular to the ridge line. Thereby, the initial position of the inner pad with respect to the punch can be controlled based on the amount of warpage in the direction that tends to affect the shape of the groove-shaped member. It is possible to further suppress deviations and variations in the shapes of a plurality of press-formed products from their intended shapes.

(Method 5)
Any one of the above methods 1 to 4 obtains correlation data indicating a correlation between a warp amount of a plate material and an initial position of the movable die with respect to the die or the punch, and using the correlation data. The method may further include setting an initial position of the movable mold corresponding to the measured warpage amount of the plate material. By using the correlation data, the set value of the initial position of the movable mold corresponding to the warp amount of the plate material can be efficiently determined.

(Method 6)
In the

method

3 or 4, in the press molding, the vertical wall may be molded while the die shoulder of the die slides the plate material over a length of 25 times or more the plate thickness of the plate material.

In the pressing process for forming the vertical wall of the groove-shaped member, when the length of the die shoulder sliding on the plate is 25 times or more the plate thickness of the plate, the shape of the groove-shaped member varies due to the warp of the plate. It has been found by the inventors that this is likely to occur. When the sliding distance of the die shoulder at the time of forming the vertical wall is 25 times the plate thickness of the plate material, the effect of suppressing the deviation and variation from the target shape of the press-formed product due to the amount of warp becomes greater.

In any of the above methods 1 to 6, the tensile strength of the highest strength portion of the plate material may be 980 MPa or more. Generally, when the plate material has a high strength of 980 MPa or more, the variation in the warp amount tends to be larger than that when the plate material has a low strength. By applying any of the above methods 1 to 6 to a plate material having a strength of 980 MPa or more, it is possible to suppress the deviation or variation from the target shape of the press-formed product in the press forming of such a high-strength press object material. You can The plate material can be a metal plate. As an example, the plate material may be a steel plate.

(Structure 1)
The press line in the embodiment of the present invention includes a warp amount acquisition device that individually acquires the warp amount of one or more plate materials to be pressed for each plate material, and a die and a punch, both the punch and the die. The press device includes a movable mold that is relatively movable, and a controller that controls the press device. The controller, in the press molding of the plate material by the die of the pressing device, the punch and the mold, based on the warp amount of the plate material acquired by the warp amount acquisition device, the die of the movable mold or the Controls the initial position for the punch.

According to the above configuration 1, the initial position of the movable die with respect to the die or the punch at the time of press molding of each plate material is controlled according to the warp amount of each plate material. By controlling the initial position, the shape of the press-formed product is adjusted according to the warp amount of the plate material. Therefore, it is possible to suppress the deviation or variation of the shapes of the plurality of press-formed products from the target shape due to the variation of the warp amounts of the plurality of plate materials.

(Configuration 2)
In the configuration 1, the warp amount acquisition unit may be a warp amount measuring device that measures the warp amount of the plate material. Thereby, the individual warp amount of the plate material to be pressed can be efficiently acquired.

(Structure 3)
In Configuration 2, the punch has a top portion, a side wall, and a punch ridge line between the top portion and the side wall, and a warp measuring direction of the warp amount measuring device is a direction parallel to the punch ridge line, and It may include a direction perpendicular to the punch ridge. Accordingly, the initial position of the movable mold can be controlled based on the amount of warpage in the direction that tends to affect the shape of the press-formed product.

(Structure 4)
In any one of the above configurations 1 to 3, the height of the side wall of the punch may be 25 times or more the minimum gap between the punch and the die. In this case, when pressing the plate material with the die and the punch relatively brought close to each other with the initial position of the movable mold fixed, the sliding distance between the die shoulder and the plate material is 25 times the plate thickness of the plate material. It is easy to be above. Therefore, the effect of suppressing the deviation and variation from the target shape of the press-formed product due to the amount of warp becomes greater. The minimum gap is the distance in the pressing direction between the die and punch at the bottom dead center of molding. The pressing direction is the direction of relative movement of the die with respect to the punch.

In the above configurations 1 to 4, the press line may further include the warp amount measuring device and a controller connected to the press device. The controller can access a storage device that stores correlation data indicating a correlation between a warp amount of the plate material and an initial position of the movable mold with respect to the die or the punch.

The press line in the embodiment of the present invention includes a pressing device, a warp amount measuring device, the warp amount measuring device, and a controller connected to the press device.
The pressing device includes a die and a punch. The punch has a top portion and a side wall, a punch ridgeline between the top portion and the side wall, and an inner pad provided on the top portion.
The warp measuring direction of the warp amount measuring device includes a direction parallel to the punch ridgeline and a direction perpendicular to the punch ridgeline.
The controller, the amount of warp in the direction parallel to the punch ridgeline of the plate material measured by the warp amount measuring device and the amount of warp in the direction perpendicular to the punch ridgeline, and the allowance of the inner pad from the punch. The storage device stores correlation data indicating a correlation.

In the above configuration, the warp measurement direction of the warp amount measuring device includes a direction parallel to the punch ridgeline and a direction perpendicular to the punch ridgeline. The warp amount measuring device can measure the warp amount of the plate material. The warp amount measuring device is configured to measure the warp amount in a direction corresponding to the punch ridgeline of the plate material and a direction corresponding to a direction perpendicular to the punch ridgeline. The direction corresponding to the punch ridgeline of the plate material is the direction of the punch ridgeline with respect to the plate material when the plate material is press-molded by the pressing device. The pressing device can measure the warp amount of the plate material in the direction of the punch ridgeline and the direction perpendicular to the punch ridgeline when the plate material is press-molded.

Since the controller is connected to the warp amount measuring device and the press device, the warp amount measured by the warp amount measuring device can be used to control the initial position of the movable die in the press molding of the press device with respect to the die or punch. Further, the controller can use the correlation data stored in the storage device to determine the initial position of the movable mold corresponding to the warp amount of the plate material measured by the warp amount measuring device.

According to the above configuration, it is possible to control the initial position of the movable die in press molding (for example, the allowance from the inner pad punch) based on the warp amount of the plate material in the direction that tends to affect the shape of the press molded product. .. Therefore, it is possible to suppress the deviation from the target shape and the variation in shape of the plurality of press-formed products due to the variation in the warp amount of the plurality of plate materials.

The warp amount measuring device is configured to measure the warp amount of the plate material upstream of the press device. The controller is based on the warp amount of the plate material measured by the warp amount measuring device, and the initial position with respect to the die or punch of the movable mold when press-forming the plate material or an intermediate molded product that is a deformed product of the plate material. To control. For example, the controller sets the above-mentioned set amount when press-forming the plate material by relatively bringing the die and the punch relatively close to each other in a state where the amount of the inner pad taken out from the punch (for example, the protruding amount) is fixed to the set amount of the initial position. May be determined based on the amount of warpage.

The warp amount measuring device may be configured to measure the warp amount of the plate material before being arranged in the press device, or may be configured to measure the warp amount of the plate material arranged in the press device. ..

The controller may have a processor and a storage device. The processor executes the program stored in the storage device. The program is a program that causes the processor to execute a process of controlling the initial position of the punch or die of a possible die when press-forming the plate material based on the amount of warp of the plate material measured by the warp amount measuring device. Good.

[Embodiment]
(Press line)
FIG. 1 is a diagram showing a configuration example of a press line 100 in this embodiment. The press line 100 shown in FIG. 1 includes a conveying device 4, an intermediate forming press device 3, a press device 5, a warp amount measuring device 10, and a controller 11. The warp amount measuring device 10 is arranged upstream of the press device 5 and the intermediate forming press device 3. The warp amount measuring device 10 measures the warp amount of a plate (blank) A to be pressed, which is a flat plate material. The carrying device 4 carries the blank A to the press device 3 for intermediate forming. The press device 3 for intermediate molding deforms the blank A to obtain an intermediate molded product. In this example, the intermediate molded product press-molded by the intermediate-molding press device 3 is press-molded by the pressing device 5 into a groove-shaped member. The transport device 4 transports the intermediate molded product, that is, the press target plate B from the intermediate molding press device 3 to the press device 5.

The transfer device 4 may be, for example, a conveyor having a transfer path leading to the intermediate molding press device 3 or the press device 5. In this case, the conveying path of the conveying device 4 to the intermediate molding press device 3 may be arranged so as to pass through the measurement region of the warp amount measuring device 10. The transport device 4 is not limited to the conveyor. For example, the transport device 4 may be a manipulator configured by an articulated robot. The manipulator conveys, for example, a material table arranged upstream of the intermediate molding press device 3 or the press device 5 or a plate material placed on a mold to the press device 5. The warp amount measuring device 10 may be arranged on the material table or so as to be able to measure the warp amount of the press target plate being conveyed by the manipulator. The transport device 4 may be an unmanned or manned forklift.

The press device 5 press-molds the plate B to be pressed into a press-molded product C. Hereinafter, the “press target plate A” and the “press target plate B” are simply referred to as “plate material A” and “plate material B”. In this example, the press-formed product C is a groove-shaped member. The pressing device 5 has a die 6, a punch 7, a die side pad 8, and a punch side inner pad 9 as a die. The die-side pad 8 and the punch-side inner pad 9 can change their relative positions with respect to both the die 6 and the punch 7. The pressing device 5 arranges the plate material B between the die 6 and the punch 7 and presses the plate material B from both the die 6 and the punch 7 to press-mold the plate material B.

Specifically, the press device 5 press-molds the plate material B between the die 6 and the punch 7 while pushing the punch 7 inside the die 6 by the relative movement of the die 6 and the punch 7. In the press molding process for making one press-molded product, in a state where the punch-side inner pad 9 is in contact with the plate material B and the relative position between the punch-side inner pad and the punch 7 is fixed at a set position (initial position), A step (first pressing step) of bringing the die 6 and the punch 7 relatively close to each other and pushing the plate material B by the die 6 and the punch 7 is included. The press forming step includes a step (second pressing step) of press-forming the plate material B by bringing the die 6 and the punch 7 relatively close to each other while accommodating the punch-side inner pad 9 in the punch 7. The press molding step further includes a step of pressing the plate material B by pressing the plate material B with the punch 7 and the die 6 in a state where the punch side inner pad 9 is housed in the punch 7 (third pressing step). ..

The groove-shaped member of the press-formed product C includes a top plate, a vertical wall adjacent to the top plate, and a ridge line between the top plate and the vertical wall. Vertical walls are mainly formed in the first pressing step and the second pressing step. The top plate is mainly formed in the third pressing step.

The warp amount measuring device 10 may be configured to measure the warp amount from an image of the side surface of the plate material acquired using an optical sensor from the side surface of the plate material, for example. Alternatively, the warp amount measuring device 10 may be configured to measure the warp amount of the plate material by measuring the shape of the front surface, the back surface, or both surfaces of the plate material using a camera or a laser displacement meter. For the measurement of the shape of the surface of the plate material, for example, a light cutting method, a phase shift method, a stereo matching method, or the like can be used. The warp amount measuring device 10 may measure, for example, the maximum value of the amount of displacement of the surface of the plate material from the reference plane as the amount of warp of the plate material. As an example, it is possible to access from one side of the plate material with a laser displacement meter and measure the angle of inclination in one direction with two portions separated by a certain distance by the light section method. This angle can be converted into a warp amount.

The warp amount measuring device 10 is configured to measure the warp amount of the plate material in two or more directions. The warp amount measuring device 10 is configured to measure the warp amount of the plate material in two directions in the plane of the plate material that are orthogonal to each other, for example. For example, the warp amount measuring device 10 measures the warp amount of a plate material in each of a direction of a line which is a ridge line of the groove type member when the plate material is press-formed into a groove type member and a direction perpendicular to the line. May be configured to do so.

The controller 11 is connected to the press device 5 and the warp amount measuring device 10. Here, the controller 11 may be wired or wirelessly connected to the press device 5 and the warp amount measuring device 10. The controller 11 can communicate with the press device 5 and the warp amount measuring device 10. The controller 11 may be built in the press device 5 or the warp amount measuring device 10 or may be a device independent of them.

The controller 11 can be configured by, for example, a computer including a processor 11a and a storage device 11b (memory). The function of the controller 11 can be realized by the processor 11a executing the program stored in the storage device 11b. The controller 11 uses the data on the warp amount of the plate material (blank) A measured by the warp amount measuring device 10 to determine the initial position (for example, the punch of the punch-side inner pad 9) with respect to the die or the punch of the movable mold in the press forming. The relative position with respect to 7, that is, the amount of the inner pad 9 taken out from the punch 7 is controlled. Specifically, the controller 11 sets the initial position of the movable mold based on the data regarding the warp amount of the plate material (blank) A measured by the warp amount measuring device 10.

Here, the initial position of the movable mold set by the controller 11 is set, for example, with the die 6 and the punch 7 being relatively close to each other, with the allowance from the punch 7 of the punch-side inner pad 9 fixed at a set value. It can be set to the above-mentioned set value at the time of press molding (the above-mentioned first pressing step). That is, the controller 11 controls the set value of the stock removal in the first pressing step.

The controller 11 uses, for example, correlation data that is recorded in advance in the storage device 11b and indicates the correlation between the warp amount and the initial position of the movable mold, and the initial position of the movable mold according to the measured warp amount ( It is possible to determine the control of the margin of the inner pad on the punch side). The correlation data indicates the correspondence relationship between the initial position of the movable mold (for example, the margin of the punch-side inner pad 9 from the punch 7 during press molding (for example, in the first pressing step)) and the warp amount of the plate material. It is the data shown. Specifically, the correlation data may be data showing the correlation (correspondence) between the value indicating the warp amount of the plate material obtained by the measurement and the value controlling the initial position of the movable mold in press molding. Good. The data format of the correlation data is not particularly limited. The correlation data may be data (for example, table data, map data, etc.) that associates a value indicating the warp amount of the plate material with a value for controlling the initial position of the movable mold. Alternatively, the correlation data is data indicating the processing procedure of the processor that calculates the value for controlling the initial position of the movable mold by using the value indicating the warp amount of the plate material (for example, a function, a program or these parameters, etc.). ). The correlation data is, for example, the amount of warpage of a plurality of plate materials (for example, test blanks) measured in the past, the initial position of the movable mold when these plate materials are press-formed, and the press-formed product obtained by the press-forming. It can be created based on the shape of

For example, the controller 11 acquires data indicating the measured warp amount of the plate material (blank) A from the warp amount measuring device 10. The controller 11 uses the correlation data to convert the value indicating the warp amount of the plate material (blank) A into a control value indicating the initial position of the movable mold. The controller 11 controls the press device 5 so that the initial position of the movable mold during press molding is the position indicated by the control value.

The press device 5 repeats press forming on a plurality of plate materials B obtained by processing a plurality of blanks A included in a manufacturing lot, and manufactures a plurality of press formed products. In the press forming of each of the plurality of plate materials B, the controller 11 may set the initial position of the movable mold. The controller 11 uses the data indicating the warp amount of the original blank A of the plate material B to set the initial position of the movable mold in the press molding of one plate material B. This enables feedforward control of the initial position of the movable mold according to the warp amount of the blank A. The warp amount measuring device 10 may measure the warp amount of the plate material B, which is an intermediate molded product, instead of the blank A. In this case, the controller 11 sets the initial position of the movable mold according to the amount of warpage of the plate material B which is an intermediate product.

(Example of configuration of press device and warp amount measuring device)
FIG. 2 is a perspective view showing a configuration example of a press device 5 having a movable mold. In the example shown in FIG. 2, the movable mold includes a die 6 having a concave portion, a punch 7 having a convex portion corresponding to the concave portion of the die 6, and a die 6 and a die side movable relative to the punch 7. The pad 8 and the punch-side inner pad 9 are included. The die-side pad 8 forms a part of the recess of the die 6 and can protrude toward the punch 7 side with respect to the recess of the die 6. The punch-side inner pad 9 forms a part of the convex portion of the punch 7 and can protrude toward the die 6 side with respect to the convex portion of the punch 7.

The convex portion of the punch 7 includes a top portion 7c, a side wall 7d adjacent to the top portion 7c, and a punch ridge line 7b between the top portion 7c and the side wall 7d. In the example shown in FIG. 2, a plurality of punch-side inner pads 9 are provided. The plurality of punch-side inner pads 9 are arranged at intervals in the extending direction of the punch ridgeline 7b. The punch-side inner pad 9 may be provided in the punch 7 over the entire extension direction of the punch ridge 7b.

The recess of the die 6 includes a bottom 6a, a side wall 6b adjacent to the bottom 6a, and a die shoulder 6c that is the edge of the recess. The die shoulder 6c forms a die ridge. The extending direction of the die ridge line is substantially the same as the extending direction of the punch ridge line 7b. A plurality of die-side pads 8 are provided. The plurality of die-side pads 8 are provided at positions corresponding to the plurality of punch-side inner pads 9, respectively. The plurality of die-side pads 8 are arranged at intervals in the direction perpendicular to the plate material conveyance direction. The die side pad 8 may be provided on the entire die 6 in the extending direction of the punch ridge line 7b.

The plate material B is conveyed between the die 6 and the punch 7. The transport direction F of the plate material B is substantially perpendicular to the extending direction of the punch ridge line 7b and the die shoulder 6c. The plate material B is arranged between the die 6 and the punch 7, and is pressed by the die 6 and the punch 7 to be press-molded. The plate material B becomes a groove-shaped member by press molding. In the press-molding step, the plate material B is pressed and molded while the die shoulder 6c slides on the plate material B. Further, the plate material B is pressed against the punch ridge line 7b to form a ridge line on the plate material B. Therefore, the extending direction of the ridgeline between the top plate and the vertical wall of the groove-shaped member to be press-formed corresponds to the extending direction of the punch ridgeline 7b.

The warp amount measuring device 10 measures the warp amount in the plate material (blank) A in the direction of the line in which the ridgeline of the groove-shaped member is formed and in the direction perpendicular thereto. That is, in the plate material (blank) A, the amount of warpage in the direction of the line that the punch ridge line 7b is expected to hit by press forming and in the direction perpendicular thereto is measured.

FIG. 3A is a diagram for explaining an example of the relationship between the measurement direction of the warp amount of the blank A and the direction of the punch ridge line 7b in press molding. FIG. 3A is a top view of the blank A and the punch 7. In FIG. 3A, the surface of the blank A is the xy plane, and the direction perpendicular to the xy plane is the z direction. The x direction and the y direction are orthogonal to each other. In the example shown in FIG. 3A, the amount of warpage is measured in each of two directions in the plane of the blank A that are orthogonal to each other, that is, (the x direction and the y direction). The blank A is processed into the plate material B. The plate material B is arranged between the punch 7 and the die 6 in a state where one of the two directions (the x direction and the y direction) in which the amount of warp of the plate material B is measured is the same as the extending direction of the punch ridge line 7b. To be done. Thereby, the amount of warp in the extending direction of the ridgeline of the groove type member and the amount of warp in the direction perpendicular to the ridgeline of the groove type member are measured.

FIG. 3B is a diagram for explaining the measurement of the warp amount of the plate material (blank) A in the x direction in FIG. 3A. In the example shown in FIG. 3B, the displacement is measured from the reference plane KM on the surface of the plate material A at each point arranged in the x direction. For example, the amount of warp in the x direction can be determined based on the maximum value S1 of the displacement amount on the reference plane KM and the maximum value of the displacement amount below the reference plane KM. The reference surface KM may be, for example, a surface preset in the measurement system of the warp amount measuring device 10 or a surface determined from the measurement positions of a plurality of points of the plate material A. Thus, the amount of warpage of the plate material in one direction can be measured by the distribution of the displacement of the plate material from the reference plane in one direction. Similarly, the amount of warpage in two or more directions can be measured.

FIG. 3C is a diagram for explaining another example of measurement of the warp amount of the plate material. In the example shown in FIG. 3C, the angle of the cross section in the xz plane of two portions of the plate material A that are apart from each other by a specific distance K1 in the x direction is measured. The distance K1 may be about 110 mm, for example. The length K2 in the x direction of the portion to be measured may be, for example, about 5 mm. The integrated value of the amount of warp changes the angle. By measuring the angle change, it is possible to measure the average amount of warpage in a certain specific section. Alternatively, as another example, the z coordinate values of three points separated by a constant interval may be measured. In this case, if the surface of the plate material is assumed to have a uniform arcuate curve, the average warp amount can be obtained from the measured values at three points. The method of measuring the warp amount is not limited to the above example.

(Example of press molding)
4A to 4D are views showing an example of press molding. Here, as an example, a press molding example by the press device 5 shown in FIGS. 1 and 2 will be described. In the example shown in FIGS. 4A to 4D, the die side pad 8 is arranged inside the die 6 and is movable in the pressing direction of the plate material. Here, the pressing direction of the plate material is the direction of relative movement of the die 6 with respect to the punch 7. The punch-side inner pad 9 can be arranged so as to project outward from the pressing surface 7a of the punch 7, and can be pushed to the same height as the pressing surface 7a of the punch 7. The top surface (top surface) of the top portion 7c of the punch 7 is the pressing surface 7a.

The inner pad 9 on the punch side is movable in the vertical direction (pressurizing direction) with respect to the punch 7 via an elevating mechanism such as a gas spring 9s or a cushion mechanism of a press machine. The die side pad 8 is installed on the slide 6d of the press device via an elevating mechanism such as a gas spring 8s. The die 6 is fixed to the slide 6d. The die side pad 8 is movable in the vertical direction together with the slide 6d. The distance between the die side pad 8 and the slide 6d can be expanded and contracted by the gas spring 8s. The bottom 6a of the recess of the die 6 is provided with a recess in which the die side pad 8 is placed. The punch-side inner pad 9 is arranged inside the recess formed in the pressing surface 7 a of the punch 7. Further, the punch-side inner pad 9 is urged upward by the gas spring 9s arranged inside the recess. Due to the biasing of the gas spring 9s, the upper surface of the punch-side inner pad 9 is in a state of being projected to the outside of the pressing surface 7a of the punch 7. The distance between the punch 7 and the punch-side inner pad 9 changes due to the expansion and contraction of the gas spring 9s.

The die side pad 8 and the punch side inner pad 9 are movable relative to the die 6 or the punch 7 while being pressed against the plate material B. For example, the die 6 can be brought close to the punch 7 while the die side pad 8 and the punch side inner pad 9 are stationary with the plate material B sandwiched therebetween. When the die pad 8 and the punch inner pad 9 sandwiching the plate material B stand still while the slide 6d, that is, the die 6 moves toward the punch 7, the gas spring 8s (elevating mechanism) of the die pad 8 Shrinks. When the die side pad 8 moves toward the punch 7 while the die 6 moves toward the punch 7, the gas spring 8s (elevating mechanism) of the die side pad 8 does not expand or contract.

The pressing device 5 presses the punch-side inner pad 9 and the die-side pad 8 against the plate material B in a state where the punch-side inner pad 9 is projected outward from the pressing surface 7a of the punch 7, while pressing the die 6 and the punch 7 together. And are relatively close to each other, and the plate material B is press-molded. The plate material B is press-molded until the inner pad 9 on the punch side has the same height as the pressing surface 7a of the punch 7 at the bottom dead center of the molding. At the bottom dead center of molding, the plate material B is sandwiched between the punch 7 and the die 6 with the punch-side inner pad 9 accommodated in the punch 7 and the die-side pad 8 accommodated in the die 6.

As a specific example, first, as shown in FIG. 4A, while the die-side pad 8 is pressed against the plate material B while the punch-side inner pad 9 is projected outward from the pressing surface 7a of the punch 7, the die 6 and The plate material B is press-formed between the die 6 and the punch 7 by lowering the die side pad 8. At this time, the amount of protrusion of the punch-side inner pad 9 from the punch 7, that is, the height (protrusion amount) H of the upper surface of the punch-side inner pad 9 with respect to the pressing surface 7a of the punch 7 is fixed to a set value. The amount of protrusion H is set based on the amount of warpage of the blank A before processing the plate material B, which is measured before press forming. In the plate material B to be formed, a slack Ba is generated in the plate material B in accordance with the protruding amount (protruding amount) H of the punch-side inner pad 9 from the punch 7. Then, as shown in FIG. 4B, the press molding is continued by lowering the die 6 while controlling the slack Ba of the plate material B to a predetermined amount from this state. As shown in FIG. 4C, the die 6 is moved down to a position before the bottom dead center H of the molding (a position H from the bottom dead center of the molding). At this time, the die 6 descends while the pressing mechanism of the die side pad 8 contracts.

In the steps shown in FIGS. 4A to 4C, the die 6 and the punch 7 are moved relative to each other in a state where the amount of protrusion of the punch 7 from the punch-side inner pad 9, that is, the protruding amount H is fixed at a set value (a value indicating the initial position). Close to each other. From the stage shown in FIG. 4C, that is, the stage in which the die side pad 8 is completely accommodated by being bottomed with respect to the die 6 (the stage before the amount of protrusion H from the bottom dead center of the molding), the punch side inner pad 9 The distance between the upper surface of the punch 7 and the pressing surface 7a of the punch 7 begins to shrink. From the stage of FIG. 4C to the stage of FIG. 4D, the relative position of the punch 7 with respect to the punch-side inner pad 9 changes. As shown in FIG. 4D, the plate material B is press-molded until the upper surface of the punch-side inner pad 9 has the same height as the pressing surface 7 a of the punch 7. At this time, the slack Ba formed on the plate material B is discharged toward the vertical wall portion between the punch 7 and the die 6 while receiving in-plane compressive stress. This makes it possible to obtain a press-formed product having a hat-shaped cross section.

In the example shown in FIGS. 4A to 4D, the slack Ba formed on the plate material B is squeezed out and flowed out toward the vertical wall portion, so that the bending region contributing inward, that is, the spring go is expanded. This makes it possible to balance the spring back and spring go of the material to be press-formed. As a result, defective vertical wall shapes can be reduced.

4A to 4D, the outer part Bb of the plate material B sandwiched between the die side pad 8 and the punch side inner pad 9 slides on the die 6 and the punch 7. Pressed. It has been found that the warp of the plate material portion Bb sliding on the die 6 or the punch 7 in this press molding tends to affect the shape of the press molded product. Therefore, when the sliding distance between the die shoulder 6c of the die 6 and the plate material B is 25 times or more the plate thickness of the plate material B, the effect of controlling the feeding amount H based on the amount of warp becomes greater.

In the above-mentioned example, in the press forming for one plate B, the die 6 is brought relatively close to the punch 7 in a state where the allowance of the punch-side inner pad 9 from the punch 7 is fixed (state of press initialization). A step of press-forming the plate material B, and a step of changing the amount of the punch-side inner pad 9 from the punch 7 to bring the die 6 closer to the punch 7 and press-forming the plate material B. The amount of protrusion of the punch-side inner pad 9 from the punch 7, that is, the protrusion amount H of the punch-side inner pad 9 in the initial setting of the press is controlled by the controller 11. The protrusion amount H is an example of a value indicating the initial position of the movable mold.

The controller 11 determines the protruding amount H of the punch-side inner pad 9 based on the measured warp amount of the plate material (blank) A. In the example shown in FIG. 3A, the warp amount of the plate material (blank) A is measured in the extending direction of the ridgeline of the groove-shaped member of the press-formed product, that is, the extending direction of the punch ridgeline 7b and the direction perpendicular thereto. As a result, the protrusion amount H of the punch-side inner pad 9 can be controlled according to the warp amount of the plate material (blank) A in the direction that tends to affect the shape of the press-formed product.

Note that press molding using a movable mold is not limited to the above example. For example, the die side pad 8 can be omitted in the press machine. Further, although the above example is an example of press-forming the plate material B which is an intermediate raw material that has been bent and formed in advance, the press device may press the flat plate that is not bent, that is, the blank A.

Generally, in bending, the die side pad is often set to prevent displacement of the plate material with respect to the punch side inner pad. In other words, the die-side pad may be omitted in the case of a shape that is not easily displaced. In the molding examples shown in FIGS. 4A to 4D, the die side pad 8 may be omitted in some cases. In the molding example shown in FIGS. 4A to 4D, when the die side pad 8 is omitted, the portion corresponding to the die side pad 8 is housed in the recess of the die 6 from the initial stage of molding to the stage shown in FIG. 4C. In this state, the die is integrated with the die. From the initial stage of forming to the stage shown in FIG. 4C, the center portion of the plate material B in the cross-sectional width direction is pressed from below by the punch-side inner pad 9 as in the case of the die-side pad 8. Advances. After the step shown in FIG. 4C, the punch-side inner pad 9 is pushed downward by the die 6 and descends, and the press forming is completed as in FIG. 4D.

(Example of press-formed products)
FIG. 5 is a cross-sectional view showing an example of a press-formed product. The press-formed product 12 shown in FIG. 5 is obtained, for example, by the press-forming shown in FIGS. 4A to 4D. The press-formed product 12 is an example of a groove-shaped member. The press-formed product 12 has a hat-shaped cross section. The press-formed product 12 is a long member whose longitudinal direction is the direction perpendicular to the cross section shown in FIG. It includes a top plate 12A extending in the width direction of the press-formed product 12 and a pair of ridge lines 12B adjacent to both ends of the top plate 12A in the width direction. The press-formed product 12 includes a pair of vertical walls 12C extending from the ridgeline 12B to the back surface side (one side in the plate thickness direction) of the top plate 12A, and a pair of vertical walls 12C adjacent to the tips (lower ends) of the vertical walls 12C. Including the ridge 12D. Further, the press-formed product 12 includes a pair of flanges 12E extending from the pair of ridge lines 12D to both sides of the top plate 12A in the width direction. The angle θ2 formed by the top plate 12A and the vertical wall 12C is 90 deg. Not limited to. The angle θ2 is 90 to 125 deg. Can be illustrated. In the case of heavy working within this range, problems such as springback become particularly apparent, so that the control of the stock removal amount based on the warp amount becomes effective. The angle θ2 is 90 deg. If the acute angle is less than 100 mm, it may be difficult to remove the press-formed product from the mold.

In the press-formed product 12, for example, the angle θ1 formed by the top plate 12A and the flange 12E may be measured. In this example, each θ1 formed by the top plate 12A and the flange 12E is a predetermined reference value θc indicating a desired shape, in this case 0 deg. When it is larger than (θ1>θc=0 deg. ), it becomes a springback, and when θ1 is smaller than the reference value θc (θ1<θc=0 deg. ), it becomes a spring go. The value indicating the degree of spring back or spring go is not limited to the angle θ1 in the above example. For example, the angle θ2 formed by the top plate 12A and the flange 12E, the vertical height difference T1 of the bottom surface of the flange 12E, or the like may be measured as a value indicating the degree of springback or spring go.

(Operation example)
FIG. 6 is a flowchart showing an operation example of the controller 11 in this embodiment. In the example shown in FIG. 6, first, the controller 11 initializes press conditions (S1). The pressing conditions include, for example, the initial position of the movable die with respect to the die or punch (as an example, the allowance of the punch-side inner pad 9 from the punch). As an example of the initial position of the movable mold, the initial value of the protrusion amount H of the punch-side inner pad 9 is set. The pressing condition is not limited to the initial position of the movable mold.

The controller 11 acquires the previously obtained correlation data (S2). For example, the controller 11 determines the correlation data to be used in the feedforward process and makes it accessible. For example, the correlation data used for the processing is extracted from the data recorded in advance in the recording medium accessible to the computer of the controller 11 (the storage device built in or external to the controller 11) and stored in the memory (storage device 11b). To do. The correlation data is created in advance before press molding and recorded in a storage medium accessible by the controller 11.

In S3 of FIG. 6, the warp amount measuring device 10 acquires the measurement result of the warp amount of the plate material B that is subsequently conveyed to the press device 5. The controller 11 acquires the measurement result of the warp amount of the plate material from the warp amount measuring device 10. As an example, as shown in FIGS. 1 and 2, the amount of warpage of the plate material (blank) A is measured upstream of the press device 5. The data indicating the warp amount of the plate material (blank) A is stored in, for example, a storage device accessible by the controller 11. The controller 11 acquires, from the storage device, data indicating the warp amount of the plate material (blank) A that is the source of the plate material B that is subsequently conveyed to the press device 5.

The controller 11 sets the initial position of the movable mold, for example, the amount of protrusion (protruding amount H) of the punch-side inner pad 9 with respect to the punch, based on the warp amount acquired in S3 (S4). The controller 11 controls the press device 5 so that the protrusion amount H of the punch-side inner pad 9 with respect to the punch 7 becomes a value set based on the warp amount. The controller 11 executes press molding while controlling the protrusion amount H (S5). In S5, the press forming is performed on the plate material B processed from the blank A whose warp amount is acquired in S3 with the allowance (protrusion amount H) of the punch-side inner pad 9 set in S4.

The processing of S3 to S5 in FIG. 6 is repeated for a plurality of plate materials included in one manufacturing lot. This enables feedforward control based on the warp amount of the plate material in each press forming of one manufacturing lot.

Here, an example of correlation data will be described. The graph shown in FIG. 7 shows the relationship between the protrusion amount H of the punch-side inner pad 9 and the spring back/spring go. The angle difference on the vertical axis of the graph is the angle θ1 between the top plate 12A and the flange 12E of the press-formed product 12 shown in FIG. 5 and the reference value θc, in this case 0 deg. And (θ1-θc (here, θc=0 deg.)). The reference value θc is an angle formed by the top plate and the flange 12E when there is no spring back or spring go. If the angle difference is positive, it means spring back, and if the angle difference is negative, it means spring go. In the relationship shown in the graph of FIG. 7, the appropriate value Ha of the protrusion amount of the punch-side inner pad is the protrusion amount when the angle difference becomes zero.

FIG. 8 is a graph showing an example of the relationship between the proper protrusion amount and the warp amount in one direction of the blank. The vertical axis of the graph shown in FIG. 8 represents the amount of protrusion of the punch-side inner pad when the angular difference (θ1−θc) becomes 0, that is, when there is no spring bag or spring go. The horizontal axis represents the amount of warp in the width direction of the blank. Here, the width direction of the blank corresponds to a direction perpendicular to the ridgeline of the groove-shaped member and a direction perpendicular to the punch ridgeline. As shown in FIG. 8, the inventor has found that the amount of warp in the width direction of the blank and the appropriate amount of protrusion of the inner pad on the punch side are correlated with each other.

FIG. 9 is a graph showing an example of the relationship between the proper protrusion amount and the warp amount in the other direction of the blank. The vertical axis of the graph shown in FIG. 9 shows the amount of protrusion of the punch-side inner pad when the angle difference (θ1-θc) becomes 0, that is, when there is no spring bag or spring go. The horizontal axis represents the amount of warp in the longitudinal direction of the blank. Here, the longitudinal direction of the blank is a direction corresponding to the extending direction of the ridgeline of the groove-shaped member and the extending direction of the punch ridgeline. As shown in FIG. 9, the inventor has found that the amount of warp in the longitudinal direction of the blank and the amount of proper protrusion of the punch-side inner pad correlate with each other.

As an example, an example of controlling the protrusion amount when both the width-direction warp amount SW1 of the blank and the longitudinal-direction warp amount SL1 can be acquired will be described. In this case, from the sum (HW1+HL1) of the proper protrusion amount HW1 with respect to the warp amount SW1 in the width direction obtained from the graph of FIG. 8 and the proper protrusion amount HL1 with respect to the warp amount SL1 in the longitudinal direction obtained from the graph of FIG. A value obtained by subtracting the appropriate protrusion amount Hao when there is no warp amount in both the width direction and the width direction can be calculated as the protrusion amount H. The controller 11 controls the press device 5 so that the amount of protrusion of the inner pad 9 on the punch side from the punch 7, that is, the set value of the protrusion amount H is (HW1+HL1-Hao). In this case, for example, the formula representing the lines of the graphs shown in FIGS. 8 and 9 or the data representing each plot in the graph is used as the correlation data.

In this way, the correlation data may include data indicating the relationship between the amount of warp in the width direction of the plate material and the amount of warp in the length direction of the plate material, and the appropriate value of the stock allowance of the punch-side inner pad. By using such correlation data, the controller 11 can determine an appropriate protrusion amount based on the measured warpage amounts in the width direction and the longitudinal direction of the plate material. As a result, it is possible to more appropriately control the feeding amount based on the amount of warpage of the plate material in the direction that tends to affect the press-formed product.

(Example of plate material)
The material of the plate material to which the present invention is applicable is not particularly limited. As the material of the plate material, for example, a thin plate of 980 MPa class high strength steel sheet (High Tensile Strength Steel Sheets) may be used. In recent years, in order to reduce the weight of press-molded products, the strength of press-molded products has been increasing. At the same time, the strength of press-molded materials is also increasing. As the strength of the material increases, it becomes difficult to press-form into a desired shape. For example, spring packs generally tend to be larger as the material becomes stronger. According to the above-described embodiment, even when a plate material having a tensile strength of 980 MPa or more is used, it is possible to reduce deviations and variations in the shapes of a plurality of press-formed products from their intended shapes.

Further, in general, for example, between a steel plate having a tensile strength of 270 MPa and a steel plate of 1.2 GPa, the variation in the amount of warpage tends to be larger in the steel plate of 1.2 GPa. If there is a large variation in the amount of warpage, adjust the mold shape and even if the shape of the press-molded product that was press-molded at the beginning of the manufacturing lot is the desired shape, press-molded products that are later press-molded within the manufacturing lot may also be used. There is a high probability that the target shape will not be achieved. According to the above-described embodiment, even when a plate material having a tensile strength of 980 MPa or more, which is relatively large compared to a steel sheet having a low strength in the characteristics of the material, is used, the inner pad punch based on the warp amount is used. By performing feed-forward control of the feeding margin, it is possible to reduce variations in the shapes of a plurality of press-formed products.

(Example)
FIG. 10 is a histogram showing the result of measuring the positional accuracy of the flange when the amount H of protrusion of the punch-side inner pad 9 is feedforward controlled based on the amount of warpage. FIG. 11 is a histogram showing the result of measuring the position accuracy of the flange when the feed-forward control is not performed on the protrusion amount H of the punch-side inner pad 9. 10 and 11, the first histogram from the top shows the distribution of the warp amount in the width direction of blanks included in one test lot. The warp in the width direction of the blank is randomly changed within each range of about −0.0004 to 0.0006 mm ⁻¹ for each press-forming shot. The second histogram from the top shows the distribution of the warp amount in the longitudinal direction of blanks included in one test lot. The warp in the longitudinal direction of the blank is within the range of about −0.0004 to 0.0004 mm ⁻¹ and randomly changes for each press molding shot. The third histogram from the top shows the distribution of flange position accuracy in one test lot. The flange position accuracy is the difference in height of the flange (corresponding to T1 shown in FIG. 5). As for the flange position accuracy, the target reference position is 0.0. As the blank material, a steel plate having a tensile strength of 1180 MPa was used.

In the results shown in FIG. 10, the standard deviation of the warp in the width direction of the blank is 0.00023 mm-1, and the standard deviation of the warp in the longitudinal direction of the blank is 0.00018 mm-1, which is the standard of the flange position accuracy. The deviation was 0.12 mm.

In the result shown in FIG. 11, the standard deviation of the warp in the width direction of the blank is 0.00024 mm-1, and the standard deviation of the warp in the longitudinal direction of the blank is 0.00016 mm-1, which is the standard of the flange position accuracy. The deviation was 0.36 mm.

From these results, the feed-forward control for controlling the amount of protrusion (protruding amount) H of the punch-side inner pad 9 from the punch 7 based on the amount of warp of the blank is performed, so that the shape of the press-formed product is changed from the target shape. It was found that the deviation and variation can be suppressed.

Although one embodiment of the present invention has been described above, the above-described embodiment is merely an example for carrying out the present invention. Therefore, the present invention is not limited to the above-described embodiments, and can be implemented by appropriately modifying the above-described embodiments without departing from the spirit thereof.

For example, in the above embodiment, the movable die that controls the initial position based on the warp amount is the inner pad of the punch, but the initial position of the die side pad provided on the die with respect to the die is controlled based on the warp amount. May be done.

In the above embodiment, the warp amount acquisition device that acquires the warp amount is the warp amount measurement device. The warp amount acquisition device may be a device that acquires data indicating the respective warp amounts of the plurality of plate materials B to be pressed. For example, when the warp amount measuring device is in a remote place, the warp amount acquiring device may receive the warp amount measuring device or data indicating the warp amount from another communication device. The warp amount acquisition device may be included in the controller. That is, the controller may be configured to acquire the warp amount from an external device. The data indicating the warp amount of each plate material is preferably data of the actual measurement value of the warp amount, but the data indicating the warp amount is not limited to the data of the actual measurement value.

4: Transfer device 5: Press device 6: Die 7: Punch 8: Die side pad 9: Punch side inner pad (inner pad)
10: Warp amount measuring device 11: Controller 12: Press-formed product

Claims

Acquiring the warp amount of one or more pressed plate materials individually for each plate material,
Press-molding the plate material into a press-molded product by a die, a punch, and a movable mold whose relative position can be changed with respect to both the die and the punch,
In the press molding, a method of manufacturing a press molded product, wherein an initial position of the movable mold with respect to the die or the punch is controlled based on a warp amount of the plate material.
The press forming includes continuously press forming a plurality of plate materials,
The method for manufacturing a press-formed product according to claim 1, wherein an initial position of the movable die with respect to the die or the punch is controlled based on a warp amount of the plate material at least once in a plurality of press-molding operations.
The press-formed product is a grooved member having a top plate, a vertical wall extending from both ends of the top plate, and a ridge line between the top plate and the vertical wall,
The movable mold includes an inner pad provided on the top of the punch,
Placing the plate between a die and a punch with an inner pad on the top,
Setting an initial position of the inner pad with respect to the punch based on the obtained warp amount,
In a state where the initial position of the inner pad with respect to the punch is set, the die and the punch are relatively brought close to each other, and the die shoulder of the die slides the plate material to form the vertical wall,
Forming the top plate by pressing the plate material with the top of the punch accommodating the inner pad and the die.
The method for producing a press-formed product according to claim 1, which comprises:
The method for manufacturing a press-formed product according to claim 3, wherein a first warp amount in the extending direction of the ridgeline and a second warp amount in a direction perpendicular to the ridgeline are measured as the warp amount of the plate material.
Acquiring correlation data indicating the correlation between the warp amount of the plate material and the initial position of the movable die with respect to the die or the punch, and
The press-formed product according to any one of claims 1 to 4, further comprising: using the correlation data, setting an initial position of the movable mold corresponding to the measured warpage amount of the plate material. Manufacturing method.
The method of manufacturing a press-formed product according to claim 3 or 4, wherein the vertical wall is formed while the die shoulder of the die slides the plate material over a length of 25 times or more the plate thickness of the plate material.
A warp amount acquisition device for individually acquiring the warp amount of one or a plurality of plate materials to be pressed,
A press device including a die, a punch, and a movable die that can move relative to both the punch and the die;
A controller for controlling the press device,
The controller, in the press molding of the plate material by the die of the pressing device, the punch and the movable mold, based on the warp amount of the plate material acquired by the warp amount acquisition device, the die of the movable mold or A press line that controls the initial position for the punch.
The press line according to claim 7, wherein the warp amount acquisition unit is a warp amount measuring device that measures the warp amount of the plate material.
The punch has a top portion and a side wall, and a punch ridge between the top portion and the side wall,
The press line according to claim 8, wherein a warp measuring direction of the warp amount measuring device includes a direction parallel to the punch ridgeline and a direction perpendicular to the punch ridgeline.
The press line according to any one of claims 7 to 9, wherein the height of the side wall of the punch is 25 times or more the minimum gap between the punch and the die.
11. The controller according to claim 7, wherein the controller can access a storage device that stores correlation data indicating a correlation between a warp amount of a plate material and an initial position of the movable mold with respect to the die or the punch. The press line according to item 1.